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#ifndef UNITY_PACKING_INCLUDED
#define UNITY_PACKING_INCLUDED
//-----------------------------------------------------------------------------
// Normal packing
//-----------------------------------------------------------------------------
real3 PackNormalMaxComponent(real3 n)
{
// TODO: use max3
return (n / max(abs(n.x), max(abs(n.y), abs(n.z)))) * 0.5 + 0.5;
}
real3 UnpackNormalMaxComponent(real3 n)
{
return normalize(n * 2.0 - 1.0);
}
// Ref: http://jcgt.org/published/0003/02/01/paper.pdf
// Encode with Oct, this function work with any size of output
// return real between [-1, 1]
real2 PackNormalOctEncode(real3 n)
{
//real l1norm = dot(abs(n), 1.0);
//real2 res0 = n.xy * (1.0 / l1norm);
//real2 val = 1.0 - abs(res0.yx);
//return (n.zz < real2(0.0, 0.0) ? (res0 >= 0.0 ? val : -val) : res0);
// Optimized version of above code:
n *= rcp(dot(abs(n), 1.0));
real t = saturate(-n.z);
return n.xy + (n.xy >= 0.0 ? t : -t);
}
real3 UnpackNormalOctEncode(real2 f)
{
real3 n = real3(f.x, f.y, 1.0 - abs(f.x) - abs(f.y));
//real2 val = 1.0 - abs(n.yx);
//n.xy = (n.zz < real2(0.0, 0.0) ? (n.xy >= 0.0 ? val : -val) : n.xy);
// Optimized version of above code:
real t = max(-n.z, 0.0);
n.xy += n.xy >= 0.0 ? -t.xx : t.xx;
return normalize(n);
}
real2 PackNormalHemiOctEncode(real3 n)
{
real l1norm = dot(abs(n), 1.0);
real2 res = n.xy * (1.0 / l1norm);
return real2(res.x + res.y, res.x - res.y);
}
real3 UnpackNormalHemiOctEncode(real2 f)
{
real2 val = real2(f.x + f.y, f.x - f.y) * 0.5;
real3 n = real3(val, 1.0 - dot(abs(val), 1.0));
return normalize(n);
}
// Tetrahedral encoding - Looks like Tetra encoding 10:10 + 2 is similar to oct 11:11, as oct is cheaper prefer it
// To generate the basisNormal below we use these 4 vertex of a regular tetrahedron
// v0 = real3(1.0, 0.0, -1.0 / sqrt(2.0));
// v1 = real3(-1.0, 0.0, -1.0 / sqrt(2.0));
// v2 = real3(0.0, 1.0, 1.0 / sqrt(2.0));
// v3 = real3(0.0, -1.0, 1.0 / sqrt(2.0));
// Then we normalize the average of each face's vertices
// normalize(v0 + v1 + v2), etc...
static const real3 tetraBasisNormal[4] =
{
real3(0., 0.816497, -0.57735),
real3(-0.816497, 0., 0.57735),
real3(0.816497, 0., 0.57735),
real3(0., -0.816497, -0.57735)
};
// Then to get the local matrix (with z axis rotate to basisNormal) use GetLocalFrame(basisNormal[xxx])
static const real3x3 tetraBasisArray[4] =
{
real3x3(-1., 0., 0.,0., 0.57735, 0.816497,0., 0.816497, -0.57735),
real3x3(0., -1., 0.,0.57735, 0., 0.816497,-0.816497, 0., 0.57735),
real3x3(0., 1., 0.,-0.57735, 0., 0.816497,0.816497, 0., 0.57735),
real3x3(1., 0., 0.,0., -0.57735, 0.816497,0., -0.816497, -0.57735)
};
// Return [-1..1] vector2 oriented in plane of the faceIndex of a regular tetrahedron
real2 PackNormalTetraEncode(real3 n, out uint faceIndex)
{
// Retrieve the tetrahedra's face for the normal direction
// It is the one with the greatest dot value with face normal
real dot0 = dot(n, tetraBasisNormal[0]);
real dot1 = dot(n, tetraBasisNormal[1]);
real dot2 = dot(n, tetraBasisNormal[2]);
real dot3 = dot(n, tetraBasisNormal[3]);
real maxi0 = max(dot0, dot1);
real maxi1 = max(dot2, dot3);
real maxi = max(maxi0, maxi1);
// Get the index from the greatest dot
if (maxi == dot0)
faceIndex = 0;
else if (maxi == dot1)
faceIndex = 1;
else if (maxi == dot2)
faceIndex = 2;
else //(maxi == dot3)
faceIndex = 3;
// Rotate n into this local basis
n = mul(tetraBasisArray[faceIndex], n);
// Project n onto the local plane
return n.xy;
}
// Assume f [-1..1]
real3 UnpackNormalTetraEncode(real2 f, uint faceIndex)
{
// Recover n from local plane
real3 n = real3(f.xy, sqrt(1.0 - dot(f.xy, f.xy)));
// Inverse of transform PackNormalTetraEncode (just swap order in mul as we have a rotation)
return mul(n, tetraBasisArray[faceIndex]);
}
// Unpack from normal map
real3 UnpackNormalRGB(real4 packedNormal, real scale = 1.0)
{
real3 normal;
normal.xyz = packedNormal.rgb * 2.0 - 1.0;
normal.xy *= scale;
return normalize(normal);
}
real3 UnpackNormalAG(real4 packedNormal, real scale = 1.0)
{
real3 normal;
normal.xy = packedNormal.wy * 2.0 - 1.0;
normal.xy *= scale;
normal.z = sqrt(1.0 - saturate(dot(normal.xy, normal.xy)));
return normal;
}
// Unpack normal as DXT5nm (1, y, 0, x) or BC5 (x, y, 0, 1)
real3 UnpackNormalmapRGorAG(real4 packedNormal, real scale = 1.0)
{
// This do the trick
packedNormal.w *= packedNormal.x;
return UnpackNormalAG(packedNormal, scale);
}
//-----------------------------------------------------------------------------
// HDR packing
//-----------------------------------------------------------------------------
// HDR Packing not defined in GLES2
#if !defined(SHADER_API_GLES)
// Ref: http://realtimecollisiondetection.net/blog/?p=15
real4 PackToLogLuv(real3 vRGB)
{
// M matrix, for encoding
const real3x3 M = real3x3(
0.2209, 0.3390, 0.4184,
0.1138, 0.6780, 0.7319,
0.0102, 0.1130, 0.2969);
real4 vResult;
real3 Xp_Y_XYZp = mul(vRGB, M);
Xp_Y_XYZp = max(Xp_Y_XYZp, real3(1e-6, 1e-6, 1e-6));
vResult.xy = Xp_Y_XYZp.xy / Xp_Y_XYZp.z;
real Le = 2.0 * log2(Xp_Y_XYZp.y) + 127.0;
vResult.w = frac(Le);
vResult.z = (Le - (floor(vResult.w * 255.0)) / 255.0) / 255.0;
return vResult;
}
real3 UnpackFromLogLuv(real4 vLogLuv)
{
// Inverse M matrix, for decoding
const real3x3 InverseM = real3x3(
6.0014, -2.7008, -1.7996,
-1.3320, 3.1029, -5.7721,
0.3008, -1.0882, 5.6268);
real Le = vLogLuv.z * 255.0 + vLogLuv.w;
real3 Xp_Y_XYZp;
Xp_Y_XYZp.y = exp2((Le - 127.0) / 2.0);
Xp_Y_XYZp.z = Xp_Y_XYZp.y / vLogLuv.y;
Xp_Y_XYZp.x = vLogLuv.x * Xp_Y_XYZp.z;
real3 vRGB = mul(Xp_Y_XYZp, InverseM);
return max(vRGB, real3(0.0, 0.0, 0.0));
}
// The standard 32-bit HDR color format
uint PackToR11G11B10f(float3 rgb)
{
uint r = (f32tof16(rgb.x) << 17) & 0xFFE00000;
uint g = (f32tof16(rgb.y) << 6) & 0x001FFC00;
uint b = (f32tof16(rgb.z) >> 5) & 0x000003FF;
return r | g | b;
}
float3 UnpackFromR11G11B10f(uint rgb)
{
float r = f16tof32((rgb >> 17) & 0x7FF0);
float g = f16tof32((rgb >> 6) & 0x7FF0);
float b = f16tof32((rgb << 5) & 0x7FE0);
return float3(r, g, b);
}
#endif // SHADER_API_GLES
//-----------------------------------------------------------------------------
// Quaternion packing
//-----------------------------------------------------------------------------
// Ref: https://cedec.cesa.or.jp/2015/session/ENG/14698.html The Rendering Materials of Far Cry 4
/*
// This is GCN intrinsic
uint FindBiggestComponent(real4 q)
{
uint xyzIndex = CubeMapFaceID(q.x, q.y, q.z) * 0.5f;
uint wIndex = 3;
bool wBiggest = abs(q.w) > max3(abs(q.x), qbs(q.y), qbs(q.z));
return wBiggest ? wIndex : xyzIndex;
}
// Pack a quaternion into a 10:10:10:2
real4 PackQuat(real4 quat)
{
uint index = FindBiggestComponent(quat);
if (index == 0) quat = quat.yzwx;
if (index == 1) quat = quat.xzwy;
if (index == 2) quat = quat.xywz;
real4 packedQuat;
packedQuat.xyz = quat.xyz * FastSign(quat.w) * sqrt(0.5) + 0.5;
packedQuat.w = index / 3.0;
return packedQuat;
}
*/
// Unpack a quaternion from a 10:10:10:2
real4 UnpackQuat(real4 packedQuat)
{
uint index = (uint)(packedQuat.w * 3.0);
real4 quat;
quat.xyz = packedQuat.xyz * sqrt(2.0) - (1.0 / sqrt(2.0));
quat.w = sqrt(1.0 - saturate(dot(quat.xyz, quat.xyz)));
if (index == 0) quat = quat.wxyz;
if (index == 1) quat = quat.xwyz;
if (index == 2) quat = quat.xywz;
return quat;
}
// Integer and Float packing not defined in GLES2
#if !defined(SHADER_API_GLES)
//-----------------------------------------------------------------------------
// Integer packing
//-----------------------------------------------------------------------------
// Packs an integer stored using at most 'numBits' into a [0..1] real.
real PackInt(uint i, uint numBits)
{
uint maxInt = (1u << numBits) - 1u;
return saturate(i * rcp(maxInt));
}
// Unpacks a [0..1] real into an integer of size 'numBits'.
uint UnpackInt(real f, uint numBits)
{
uint maxInt = (1u << numBits) - 1u;
return (uint)(f * maxInt + 0.5); // Round instead of truncating
}
// Packs a [0..255] integer into a [0..1] real.
real PackByte(uint i)
{
return PackInt(i, 8);
}
// Unpacks a [0..1] real into a [0..255] integer.
uint UnpackByte(real f)
{
return UnpackInt(f, 8);
}
// Packs a [0..65535] integer into a [0..1] real.
real PackShort(uint i)
{
return PackInt(i, 16);
}
// Unpacks a [0..1] real into a [0..65535] integer.
uint UnpackShort(real f)
{
return UnpackInt(f, 16);
}
// Packs 8 lowermost bits of a [0..65535] integer into a [0..1] real.
real PackShortLo(uint i)
{
uint lo = BitFieldExtract(i, 0u, 8u);
return PackInt(lo, 8);
}
// Packs 8 uppermost bits of a [0..65535] integer into a [0..1] real.
real PackShortHi(uint i)
{
uint hi = BitFieldExtract(i, 8u, 8u);
return PackInt(hi, 8);
}
real Pack2Byte(real2 inputs)
{
real2 temp = inputs * real2(255.0, 255.0);
temp.x *= 256.0;
temp = round(temp);
real combined = temp.x + temp.y;
return combined * (1.0 / 65535.0);
}
real2 Unpack2Byte(real inputs)
{
real temp = round(inputs * 65535.0);
real ipart;
real fpart = modf(temp / 256.0, ipart);
real2 result = real2(ipart, round(256.0 * fpart));
return result * (1.0 / real2(255.0, 255.0));
}
// Encode a real in [0..1] and an int in [0..maxi - 1] as a real [0..1] to be store in log2(precision) bit
// maxi must be a power of two and define the number of bit dedicated 0..1 to the int part (log2(maxi))
// Example: precision is 256.0, maxi is 2, i is [0..1] encode on 1 bit. f is [0..1] encode on 7 bit.
// Example: precision is 256.0, maxi is 4, i is [0..3] encode on 2 bit. f is [0..1] encode on 6 bit.
// Example: precision is 256.0, maxi is 8, i is [0..7] encode on 3 bit. f is [0..1] encode on 5 bit.
// ...
// Example: precision is 1024.0, maxi is 8, i is [0..7] encode on 3 bit. f is [0..1] encode on 7 bit.
//...
real PackFloatInt(real f, int i, real maxi, real precision)
{
// Constant
real precisionMinusOne = precision - 1.0;
real t1 = ((precision / maxi) - 1.0) / precisionMinusOne;
real t2 = (precision / maxi) / precisionMinusOne;
return t1 * f + t2 * real(i);
}
void UnpackFloatInt(real val, real maxi, real precision, out real f, out int i)
{
// Constant
real precisionMinusOne = precision - 1.0;
real t1 = ((precision / maxi) - 1.0) / precisionMinusOne;
real t2 = (precision / maxi) / precisionMinusOne;
// extract integer part
i = int((val / t2) + rcp(precisionMinusOne)); // + rcp(precisionMinusOne) to deal with precision issue (can't use round() as val contain the floating number
// Now that we have i, solve formula in PackFloatInt for f
//f = (val - t2 * real(i)) / t1 => convert in mads form
f = saturate((-t2 * real(i) + val) / t1); // Saturate in case of precision issue
}
// Define various variante for ease of read
real PackFloatInt8bit(real f, int i, real maxi)
{
return PackFloatInt(f, i, maxi, 256.0);
}
void UnpackFloatInt8bit(real val, real maxi, out real f, out int i)
{
UnpackFloatInt(val, maxi, 256.0, f, i);
}
real PackFloatInt10bit(real f, int i, real maxi)
{
return PackFloatInt(f, i, maxi, 1024.0);
}
void UnpackFloatInt10bit(real val, real maxi, out real f, out int i)
{
UnpackFloatInt(val, maxi, 1024.0, f, i);
}
real PackFloatInt16bit(real f, int i, real maxi)
{
return PackFloatInt(f, i, maxi, 65536.0);
}
void UnpackFloatInt16bit(real val, real maxi, out real f, out int i)
{
UnpackFloatInt(val, maxi, 65536.0, f, i);
}
//-----------------------------------------------------------------------------
// Float packing
//-----------------------------------------------------------------------------
// src must be between 0.0 and 1.0
uint PackFloatToUInt(real src, uint offset, uint numBits)
{
return UnpackInt(src, numBits) << offset;
}
real UnpackUIntToFloat(uint src, uint offset, uint numBits)
{
uint maxInt = (1u << numBits) - 1u;
return real(BitFieldExtract(src, offset, numBits)) * rcp(maxInt);
}
uint PackToR10G10B10A2(real4 rgba)
{
return (PackFloatToUInt(rgba.x, 0, 10) |
PackFloatToUInt(rgba.y, 10, 10) |
PackFloatToUInt(rgba.z, 20, 10) |
PackFloatToUInt(rgba.w, 30, 2));
}
real4 UnpackFromR10G10B10A2(uint rgba)
{
real4 ouput;
ouput.x = UnpackUIntToFloat(rgba, 0, 10);
ouput.y = UnpackUIntToFloat(rgba, 10, 10);
ouput.z = UnpackUIntToFloat(rgba, 20, 10);
ouput.w = UnpackUIntToFloat(rgba, 30, 2);
return ouput;
}
// Both the input and the output are in the [0, 1] range.
real2 PackFloatToR8G8(real f)
{
uint i = UnpackShort(f);
return real2(PackShortLo(i), PackShortHi(i));
}
// Both the input and the output are in the [0, 1] range.
real UnpackFloatFromR8G8(real2 f)
{
uint lo = UnpackByte(f.x);
uint hi = UnpackByte(f.y);
uint cb = (hi << 8) + lo;
return PackShort(cb);
}
#endif // SHADER_API_GLES
#endif // UNITY_PACKING_INCLUDED